Fuel control device, combustor, gas turbine, control method, and program

ABSTRACT

A fuel control device includes a combustion temperature estimation value calculation unit that calculates a temperature estimation value when a mixture of fuel and inflow air is burned using an atmospheric condition, an opening degree command value of a valve that controls the amount of air that is mixed with the fuel and burned, and an output prediction value calculated on the basis of a fuel control signal command value used for calculation of a total fuel flow rate flowing through a plurality of fuel supply systems, a fuel distribution command value calculation unit that calculates a fuel distribution command value indicating a distribution of fuel output from the fuel supply systems based on the temperature estimation value, and outputs the fuel distribution command value, and a valve opening degree calculation unit that calculates each valve opening degree of a fuel flow rate control valve of the fuel supply systems.

TECHNICAL FIELD

The present invention relates to a fuel control device, a combustor, agas turbine, a control method, and a program.

Priority is claimed on Japanese Patent Application No. 2014-034871,filed Feb. 26, 2014, the content of which is incorporated herein byreference.

BACKGROUND ART

In supply of fuel to a combustor of a gas turbine, the fuel is dividedand supplied to a plurality of systems in terms of efficiency orstability of combustion in some cases. In such cases, it is necessary toconsider distribution of the fuel to the respective systems.

FIG. 14 is a diagram illustrating an example of a fuel distributioncontrol of a gas turbine of the related art. As illustrated in FIG. 14,the fuel control device of the related art estimates a temperature of acombustion gas at an inlet of the turbine on the basis of an atmosphericpressure, an atmospheric temperature, an inlet guide vane (IGV) openingdegree designation value, and a gas turbine output value, and calculatesa ratio of the fuel to be assigned to respective systems on the basis ofa turbine inlet temperature estimation value. The fuel control devicedetermines a fuel supply amount for supply to a nozzle of each fuelsystem from a distribution ratio for distribution to each system and atotal fuel flow rate based on a fuel control signal command value (CSO),and controls a valve opening degree of a fuel flow rate control valveprovided in each system.

Further, combustion vibration has been known to occur in a combustor ofa gas turbine, for example, if a distribution ratio of fuel suppliedfrom a plurality of systems is changed. Since the combustion vibrationis a pressure fluctuation within the combustor and damages the combustoror components of the gas turbine, it is necessary to suppress thecombustion vibration (see Patent Literature 1).

FIG. 15 is a diagram illustrating an example of a relationship between afuel distribution ratio for distribution to a certain fuel system and aturbine inlet temperature during a load change in the related art. Asillustrated in FIG. 15, there are regions (region 74 and region 75) inwhich combustion vibration occurs according to the fuel distributionratio and a value of the turbine inlet temperature. Further, a targetoperation line 71 indicates a target operation line indicating arelationship between a fuel distribution ratio at which such acombustion vibration does not occur and a turbine inlet temperature. Inthe fuel control device, it is preferable to control the distributionratio of the fuel supplied to each system so that the fuel distributionratio becomes a fuel distribution ratio at which a combustion vibrationoccurrence region can be avoided as shown by the target operation line71.

CITATION LIST Patent Literature

[Patent Literature 1]

Japanese Unexamined Patent Application, First Publication No. 2012-92681

SUMMARY OF INVENTION Technical Problem

When an output of a gas turbine fluctuates, an inlet temperature of theturbine correspondingly changes. Particularly, if the fluctuation issharp, a turbine inlet temperature estimation value calculated as aboveis not in time for a change in an actual gas turbine inlet temperature.In this case, an operation line indicating a relationship between a fueldistribution ratio calculated by a fuel control device on the basis ofthe turbine inlet temperature estimation value and the actual gasturbine inlet temperature may be included in the combustion vibrationoccurrence region. For example, an operation line 72 is an example of anoperation line when a load increases, and an operation line 73 is anexample of an operation line when the load decreases. In either case,the combustion vibration is likely to occur.

The present invention provides a fuel control device, a combustor, a gasturbine, a control method, and a program capable of solving theabove-described problem.

Solution to Problem

According to a first aspect of the present invention, a fuel controldevice includes a combustion temperature estimation value calculationunit that calculates a temperature estimation value when a mixture offuel and inflow air is burned using an atmospheric condition, an openingdegree command value of a valve that controls the amount of air that ismixed with the fuel and burned, and an output prediction valuecalculated on the basis of a fuel control signal command value used forcalculation of a total fuel flow rate flowing through a plurality offuel supply systems; a fuel distribution command value calculation unitthat calculates a fuel distribution command value indicating adistribution of fuel output from the plurality of fuel supply systems onthe basis of the temperature estimation value, and outputs the fueldistribution command value; and a valve opening degree calculation unitthat calculates each valve opening degree of a fuel flow rate controlvalve of the plurality of fuel supply systems on the basis of the fueldistribution command value and the total fuel flow rate based on thefuel control signal command value.

According to a second aspect of the present invention, the fuel controldevice includes a gas turbine output prediction value calculation unitthat calculates the output prediction value on the basis of apredetermined correspondence relationship between the fuel controlsignal command value and an output value of a gas turbine, and the fuelcontrol signal command value.

According to a third aspect of the present invention, the fuel controldevice includes a gas turbine output correction amount calculation unitthat calculates a gas turbine output correction amount for correctingthe output prediction value on the basis of a predeterminedcorrespondence relationship between the fuel control signal commandvalue and a value for correcting an output of a gas turbine, and thefuel control signal command value; and a gas turbine output predictionvalue calculation unit that calculates the output prediction value usingan actually measured value of an output value of the gas turbine and thegas turbine output correction amount.

According to a fourth aspect of the present invention, the fuel controldevice includes a coefficient calculation unit that calculates aweighting coefficient for the gas turbine output correction amountaccording to a value indicating an output change of the gas turbine perunit time.

According to a fifth aspect of the present invention, the fuel controldevice includes a load change rate determination unit that detects anoutput change of the gas turbine per unit time and sets the gas turbineoutput correction amount to 0 when the output change is smaller than apredetermined value.

According to a sixth aspect of the present invention, a combustorincludes the above-described fuel control device.

According to a seventh aspect of the present invention, a gas turbineincludes the above-described fuel control device.

According to an eighth aspect of the present invention, in a controlmethod, a fuel control device calculates a temperature estimation valuewhen a mixture of fuel and inflow air is burned using an atmosphericcondition, an opening degree command value of a valve that controls theamount of air that is mixed with the fuel and burned, and an outputprediction value calculated on the basis of a fuel control signalcommand value used for calculation of a total fuel flow rate flowingthrough a plurality of fuel supply systems, calculates a fueldistribution command value indicating a distribution of fuel output fromthe plurality of fuel supply systems on the basis of the temperatureestimation value, and outputs the fuel distribution command value, andcalculates each valve opening degree of a fuel flow rate control valveof the plurality of fuel supply systems on the basis of the fueldistribution command value and the total fuel flow rate based on thefuel control signal command value.

According to a ninth aspect of the present invention, a program causes acomputer of a fuel control device to function as: a means thatcalculates a temperature estimation value when a mixture of fuel andinflow air is burned using an atmospheric condition, an opening degreecommand value of a valve that controls the amount of air that is mixedwith the fuel and burned, and an output prediction value calculated onthe basis of a fuel control signal command value used for calculation ofa total fuel flow rate flowing through a plurality of fuel supplysystems; a means that calculates a fuel distribution command valueindicating a distribution of fuel output from the plurality of fuelsupply systems on the basis of the temperature estimation value, andoutputs the fuel distribution command value; and a means that calculateseach valve opening degree of a fuel flow rate control valve of theplurality of fuel supply systems on the basis of the fuel distributioncommand value and the total fuel flow rate based on the fuel controlsignal command value.

Advantageous Effects of Invention

According to the fuel control device, the combustor, the gas turbine,the control method, and the program described above, it is possible tosuppress a deviation between a target fuel system fuel ratio for theturbine inlet temperature and an actual fuel system fuel ratio even in atransient period of a load change.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a system diagram of a gas turbine plant in a first embodimentaccording to the present invention.

FIG. 2 is a block diagram illustrating an example of a fuel controldevice in the first embodiment according to the present invention.

FIG. 3 is a diagram illustrating an example of a fuel distributioncontrol in the first embodiment according to the present invention.

FIG. 4 is a diagram illustrating an example of a result of applying thefuel distribution control in the first embodiment according to thepresent invention.

FIG. 5 is a diagram illustrating a modification example of the fueldistribution control in the first embodiment according to the presentinvention.

FIG. 6 is a block diagram illustrating an example of a fuel controldevice in a second embodiment according to the present invention.

FIG. 7 is a diagram illustrating an example of a fuel distributioncontrol in the second embodiment according to the present invention.

FIG. 8 is a block diagram illustrating an example of a fuel controldevice in a third embodiment according to the present invention.

FIG. 9 is a diagram illustrating an example of a fuel distributioncontrol in the third embodiment according to the present invention.

FIG. 10 is a block diagram illustrating an example of a fuel controldevice in a fourth embodiment according to the present invention.

FIG. 11 is a diagram illustrating an example of a fuel distributioncontrol in the fourth embodiment according to the present invention.

FIG. 12 is a block diagram illustrating an example of a fuel controldevice in a fifth embodiment according to the present invention.

FIG. 13 is a diagram illustrating an example of a fuel distributioncontrol in the fifth embodiment according to the present invention.

FIG. 14 is a diagram illustrating an example of a gas turbine fueldistribution control of the related art.

FIG. 15 is a diagram illustrating an example of a relationship between afuel distribution ratio and a turbine inlet temperature at the time of aload change.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, a fuel control device according to a first embodiment ofthe present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a system diagram of a gas turbine plant in this embodiment.

The gas turbine plant of this embodiment includes a gas turbine 10, apower generator 16 that generates power through driving of the gasturbine 10, and a fuel control device 50 that controls a behavior of thegas turbine 10, as illustrated in FIG. 1. The gas turbine 10 and thepower generator 16 are coupled to each other by a rotor 15.

The gas turbine 10 includes an air compressor 11 that compresses air togenerate compressed air, a combustor 12 that mixes the compressed airwith a fuel gas, burns the gas, and generates a combustion gas at a hightemperature, and a turbine 13 that is driven by the combustion gas.

An IGV 14 is provided in the air compressor 11. The IGV 14 adjusts aflow of air into the air compressor 11. A pressure gauge 22 and athermometer 23 are provided on an inlet side of the air compressor 11.The pressure gauge 22 measures atmospheric pressure and outputs theatmospheric pressure to the fuel control device 50. The thermometer 23measures atmospheric temperature and outputs the atmospheric temperatureto the fuel control device 50.

The combustor 12 is connected to a fuel supply device 21 that supplies afuel to the combustor 12. The fuel is supplied from a plurality of fuelsupply systems (a pilot system, a main system, and a top hat system) tothe combustor 12. Accordingly, valves that adjust a flow rate of thefuel for the respective fuel systems, that is, a pilot system fuel flowrate control valve 18, a main system fuel flow rate control valve 19, atop hat system fuel flow rate control valve 20 are provided between thefuel supply device 21 and the combustor 12.

The power generator 16 includes a power meter 17, which measures thepower generated by the power generator 16 and outputs the measure powerto the fuel control device 50.

The fuel control device 50 determines a distribution ratio of the fuelto be assigned to each fuel system and adjusts valve opening degrees ofthe fuel flow rate control valves included in the respective fuel supplysystems. That is, the fuel control device 50 adjusts valve openingdegrees of the pilot system fuel flow rate control valve 18, the mainsystem fuel flow rate control valve 19, and the top hat system fuel flowrate control valve 20 to control fuel flow rates of the fuel flowingfrom nozzles of each system into the combustor.

FIG. 2 is a block diagram illustrating an example of the fuel controldevice in the first embodiment according to the present invention.

A gas turbine output prediction value calculation unit 51 acquires afuel control signal command value (CSO: Control Signal Output) from agas turbine output control unit (not illustrated) that controls anoutput of the gas turbine, and calculates an output prediction value(MW) of the gas turbine on the basis of the CSO. The fuel control signalcommand value (CSO) is a control output signal for controlling the fuelflow rate that is supplied to the combustor. The calculation of the gasturbine output prediction value is performed, for example, as follows. Atable or a function in which the CSO and the gas turbine outputprediction value are associated with each other is stored in a storageunit (not illustrated) included in the fuel control device 50, and thegas turbine output prediction value calculation unit 51 reads the tableon the basis of the acquired CSO and acquires a gas turbine outputprediction value. Alternatively, if there is no output prediction valuefor a desired CSO in the table, the gas turbine output prediction valuecalculation unit 51 performs interpolation calculation using a read gasturbine output prediction value to calculate the gas turbine outputprediction value. A correspondence between the CSO and the gas turbineoutput prediction value is determined by performing, for example, asimulation or an experiment in advance. The storage unit may be astorage device connected to the fuel control device 50.

A turbine inlet temperature estimation unit 52 estimates a temperatureof the combustion gas at the inlet of the turbine. More particularly,the turbine inlet temperature estimation unit 52 acquires theatmospheric pressure from the pressure gauge 22, the atmospherictemperature from thermometer 23, an IGV opening degree command valuefrom an IGV control device (not illustrated), and the gas turbine outputprediction value from the gas turbine output prediction valuecalculation unit 51, and estimates the temperature of the combustion gasat the inlet of the turbine (a turbine inlet temperature estimationvalue) on the basis of such values. A method of estimating the turbineinlet temperature is described in, for example, Japanese UnexaminedPatent Application, First Publication No. 2007-77867. An overviewthereof will be described. A table in which a relationship between thegas turbine output and the turbine inlet temperature at each IGV openingdegree is defined, a table in which a relationship between theatmospheric temperature and the gas turbine output at each IGV openingdegree is defined, and the like are prepared in advance. In thedescribed method, a relationship among the IGV opening degree, theatmospheric temperature, the gas turbine output, and the turbine inlettemperature is obtained using the tables. In the described method, arelationship between the gas turbine output and the turbine inlettemperature considering an atmospheric pressure ratio is obtained usinga predetermined method, and the turbine inlet temperature correspondingto the gas turbine output at a predetermined IGV opening degreeconsidering an atmospheric condition is estimated using thiscorrespondence relationship.

A fuel distribution command value calculation unit 53 reads adistribution ratio for distribution to a pilot nozzle from a table or afunction in which the turbine inlet temperature estimation value and,for example, a distribution ratio of fuel supplied to the pilot nozzleare associated with each other, which is stored in the storage unit, onthe basis of the turbine inlet temperature estimation value estimated bythe turbine inlet temperature estimation unit 52. Similarly, the fueldistribution command value calculation unit 53 reads a distributionratio for distribution to a top hat nozzle from a table or a function inwhich the turbine inlet temperature estimation value and a distributionratio of fuel supplied to the top hat nozzle are associated with eachother. If the distribution ratio is expressed as a percentage, the fueldistribution command value calculation unit 53 subtracts a sum of thedistribution ratios of the pilot nozzle and the top hat nozzle from 100%to calculate a distribution ratio of the fuel supplied to another mainnozzle. If the fuel distribution command value calculation unit 53calculates the distribution ratio for distribution to each fuel system,the fuel distribution command value calculation unit 53 outputs thedistribution ratio (the fuel distribution command value) to the valveopening degree calculation unit 55. If the distribution ratio of thefuel at the turbine inlet temperature estimation value, which is atarget, is not read from, for example, the table in which the turbineinlet temperature estimation value and each distribution ratio of thefuel are determined, the distribution ratio may be calculated usinginterpolation calculation.

The total fuel flow rate calculation unit 54 acquires the CSO from thegas turbine output control unit and calculates a total fuel flow rateindicated by the CSO. The total fuel flow rate indicates a fuel flowrate that is supplied to the combustor, and is a sum of fuel that isdistributed to respective systems. The total fuel flow rate iscalculated from a correspondence table or a function of the CSO and thetotal fuel flow rate value, which is recorded in the storage unit. Thetotal fuel flow rate calculation unit 54 outputs information on thetotal fuel flow rate to the valve opening degree calculation unit 55.

The valve opening degree calculation unit 55 calculates the valveopening degree of the flow rate control valve provided in each fuelsystem on the basis of the fuel distribution command value and the totalfuel flow rate. Specifically, the valve opening degree calculation unit55 multiplies the total fuel flow rate by the distribution ratio fordistribution to each system to calculate a fuel flow rate that issupplied to each system. The valve opening degree calculation unit 55calculates a valve opening degree of each flow rate control valve usinga correspondence table or a function of the fuel flow rate and the valveopening degree command value, which is prepared for each flow ratecontrol valve. The valve opening degree calculation unit 55 controls thepilot system fuel flow rate control valve 18, the main system fuel flowrate control valve 19, and the top hat system fuel flow rate controlvalve 20 on the basis of the calculated valve opening degree. Thecorrespondence table or the function of the fuel flow rate and the valveopening degree command value is stored in the storage unit.

FIG. 3 is a diagram illustrating an example of a fuel distributioncontrol in the first embodiment according to the present invention.

The fuel distribution control of this embodiment will be described withreference to FIG. 3.

First, the gas turbine output prediction value calculation unit 51acquires a CSO from the gas turbine output control unit. The gas turbineoutput prediction value calculation unit 51 calculates a gas turbineoutput prediction value by referring to a prerecorded correspondencetable of the CSO and the gas turbine output prediction value using theacquired CSO (100).

Then, the turbine inlet temperature estimation unit 52 acquires anatmospheric pressure from the pressure gauge 22 and an atmospherictemperature from the thermometer 23. Further, the turbine inlettemperature estimation unit 52 acquires an IGV opening command valuefrom the IGV control device. Further, the turbine inlet temperatureestimation unit 52 acquires a turbine inlet temperature estimation valueestimated by the gas turbine output prediction value calculation unit51. The turbine inlet temperature estimation unit 52 estimates a turbineinlet temperature by a predetermined method using such parameters (101).

Then, the fuel distribution command value calculation unit 53 calculatesa distribution ratio of fuel that is supplied to each of the fuel supplysystems on the basis of the turbine inlet temperature (102). The fueldistribution command value calculation unit 53 outputs information ofthe distribution ratio to the valve opening degree calculation unit 55.

On the other hand, the total fuel flow rate calculation unit 54 acquiresthe CSO from the gas turbine output control unit and calculates thetotal fuel flow rate (103). The total fuel flow rate calculation unit 54outputs the information of the total fuel flow rate to the valve openingdegree calculation unit 55.

The valve opening degree calculation unit 55 multiplies the total fuelflow rate by the distribution ratio for each fuel system to calculatethe fuel flow rate that is supplied to each fuel system (104). The valveopening degree calculation unit 55 calculates a valve opening degree ofthe flow rate control valve of each system from the fuel flow to eachsystem (105). The valve opening degree calculation unit 55 controls eachflow rate control valve on the basis of the calculated valve openingcommand value.

FIG. 4 is a diagram illustrating an example of a result of applying thefuel distribution control in the first embodiment according to thepresent invention.

As illustrated in FIG. 4, when the fuel distribution control accordingto this embodiment is applied to increase or decrease a load, either anoperation line 72 when the load increases or an operation line 73 whenthe load decreases is not included in a combustion vibration occurrenceregion, unlike the result of the related art described with reference toFIG. 15.

In the method of the related art, the turbine inlet temperatureestimation value is determined according to an actual output of the gasturbine. In this case, the fuel control device of the related artdetermines a distribution ratio of fuel to actually perform control ofthe supply of the fuel to each system. As a result, a delay is causeddue to various factors until the output of the gas turbine becomes adesired value. The various factors include, for example, a mechanicaldelay (a valve operation delay, a pressure response delay, or acombustion delay) or a control delay such as time consumed for, forexample, filter processing for removing noise from a signal. Accordingto the method of the related art, when the fluctuation of the load islarge, the fuel distribution ratio is determined on the basis of theturbine inlet temperature estimation value according to the actualoutput of the gas turbine. Accordingly, the output value of the gasturbine has already changed when the valve opening degree is actuallycontrolled on the basis of the determined distribution ratio, and thecontrol using the previously calculated valve opening degree may not fitthe actual situation.

However, according to this embodiment, by calculating the turbine inlettemperature estimation value using a prediction value of the gas turbineoutput on the basis of the CSO, it is possible to proactively compensatefor a time delay of the turbine inlet temperature estimation valuecaused by feedback of an actual gas turbine output value, which mayoccur in the method of the related art, to calculate the turbine inlettemperature estimation value. Accordingly, it is possible to decrease adeviation between an operation line and a target operation line even ina transient period of a load change and to prevent the occurrence ofcombustion vibration.

FIG. 5 is a diagram illustrating a modification example of a fueldistribution control in the first embodiment according to the presentinvention.

In this modification example, a parameter other than the CSO is used forcalculation of the output prediction value of the gas turbine. Aspecific parameter is at least one of an atmospheric temperature, anatmospheric pressure, an IGV opening command value, and a fuel calorie.Other processes are the same as those in the first embodiment.

The gas turbine output prediction value calculation unit 51 calculatesthe gas turbine output prediction value on the basis of the CSO (100).Further, the gas turbine output prediction value calculation unit 51acquires at least one of the above-described parameters. For therespective parameters, the gas turbine output prediction valuecalculation unit 51 acquires the atmospheric pressure from the pressuregauge 22, the atmospheric temperature from the thermometer 23, the IGVopening command value from the IGV control device, and the fuel caloriefrom a calorimeter (not illustrated) provided in the fuel system. Thegas turbine output prediction value calculation unit 51 reads a table inwhich a value of each parameter and a correction amount of the gasturbine output prediction value are associated with each other, which isprepared for each parameter in advance, from the storage unit using theacquired parameter, and calculates a correction amount on the basis ofthe table (100B). The gas turbine output prediction value calculationunit 51 multiplies (or adds) the gas turbine output prediction valuecalculated on the basis of the CSO by (to) the correction amount toobtain a gas turbine output prediction value after correction.

According to this modification example, it is possible to calculate thefuel distribution ratio on the basis of the gas turbine outputprediction value corresponding to an actual atmospheric temperature, anactual atmospheric pressure, an actual IGV opening command value, and anactual fuel calorie. Therefore, it is possible to perform control of thefuel flow rate which further reflects a real environment and to furthersuppress a risk of combustion fluctuation. A combination of theparameters can be used.

Second Embodiment

Hereinafter, a fuel control device according to a second embodiment ofthe present invention will be described with reference to FIGS. 6 and 7.

FIG. 6 is a block diagram illustrating an example of a fuel controldevice of this embodiment.

As illustrated in FIG. 6, a fuel control device 50 in this embodimentincludes a gas turbine output correction amount calculation unit 56.Further, a method of calculating an expected output value of the gasturbine in the gas turbine output prediction value calculation unit 51is different from that in the first embodiment. Other configurations arethe same as in the first embodiment.

The gas turbine output correction amount calculation unit 56 acquires aCSO from the gas turbine output control unit and calculates a correctionamount for the output value of the gas turbine on the basis of the CSO.For the calculation of the gas turbine output value correction amount, atable in which the CSO and the gas turbine output value correctionamount are associated with each other or a function including adifferentiator is recorded in a storage unit in advance, and the gasturbine output correction amount calculation unit 56 reads the table orthe like using the acquired CSO and obtains the gas turbine output valuecorrection amount.

Then, the gas turbine output correction amount calculation unit 56 readsa predetermined weighting coefficient P from the storage unit andmultiplies the gas turbine output correction amount acquired from thegas turbine output correction amount calculation unit 56 by theweighting coefficient P. The gas turbine output correction amountcalculation unit 56 outputs the correction amount multiplied by thecoefficient P to the gas turbine output prediction value calculationunit 51.

The gas turbine output prediction value calculation unit 51 acquires anoutput value (a gas turbine output value) of the power generator 16measured by the power meter 17. The gas turbine output prediction valuecalculation unit 51 calculates the gas turbine output prediction valuefrom the gas turbine output value and the gas turbine output correctionamount acquired from the gas turbine output correction amountcalculation unit 56.

FIG. 7 is a diagram illustrating an example of a fuel distributioncontrol in the second embodiment according to the present invention.

The fuel distribution control of this embodiment will be described withreference to FIG. 7.

First, the gas turbine output correction amount calculation unit 56acquires a CSO from the gas turbine output control unit. The gas turbineoutput correction amount calculation unit 56 calculates a gas turbineoutput correction amount by referring to a prerecorded correspondencetable of the CSO and the gas turbine output correction amount using theacquired CSO (106). Alternatively, if there is no output correctionamount corresponding to a desired CSO in the table, the gas turbineoutput correction amount calculation unit 56 may calculate the outputcorrection amount through interpolation calculation.

Then, the gas turbine output correction amount calculation unit 56 readsa predetermined coefficient P from the storage unit, and multiplies thegas turbine output correction amount by the weighting coefficient P(107). The gas turbine output correction amount calculation unit 56outputs the correction amount multiplied by the weighting coefficient Pto the gas turbine output prediction value calculation unit 51.

Further, the gas turbine output prediction value calculation unit 51acquires a gas turbine output value from the power meter 17. The gasturbine output prediction value calculation unit 51 adds the gas turbineoutput value to the correction amount acquired from the gas turbineoutput correction amount calculation unit 56 to calculate a gas turbineoutput prediction value (108). Since subsequent processes are the sameas those in the first embodiment, description thereof will be omitted.

According to this embodiment, on the basis of an actually measured valueof the gas turbine output, a turbine inlet temperature is estimatedusing the gas turbine output prediction value that is corrected on thebasis of the CSO. A distribution ratio of fuel to each fuel system isdetermined using the turbine inlet temperature. Accordingly, it ispossible to perform distribution ratio control for fuel that is moresuitable for an actual situation, and further reduce a risk of theoccurrence of combustion vibration. For example, there is a case inwhich a correspondence relationship between the CSO and the gas turbineoutput prediction value is changed from the time of design, for example,due to aging degradation. In this embodiment, since an actual gasturbine output value reflecting an actual situation such as the agingdegradation is used, the accuracy of the gas turbine output predictionvalue further increases.

Third Embodiment

Hereinafter, a fuel control device according to a third embodiment ofthe present invention will be described with reference to FIGS. 8 and 9.

FIG. 8 is a block diagram illustrating an example of a fuel controldevice of this embodiment.

As illustrated in FIG. 8, a fuel control device 50 in this embodimentincludes a load change rate calculation unit 57 and a coefficientcalculation unit 58. Other configurations are the same as those in thesecond embodiment.

The load change rate calculation unit 57 acquires an output measurementvalue of the power generator 16 from the power meter 17. The load changerate calculation unit 57 calculates a change in load per unit time.

The coefficient calculation unit 58 acquires a weighting coefficient forthe gas turbine output correction amount according to the load changerate calculated by the load change rate calculation unit 57. For thecalculation of the weighting coefficient, a table or a function in whichthe load change rate and the weighting coefficient are associated witheach other is recorded in the storage unit in advance, and thecoefficient calculation unit 58 reads the table or the like and obtainsa weighting coefficient corresponding to the calculated load change.

A target rate of an output change for achieving a target output of thegas turbine which changes minute by minute with respect to the loadchange may be used in place of the load change rate instead ofcalculating the load change rate based on an actually measured value ofthe load in order to acquire the weighting coefficient. A value of thistarget rate is a value that the gas turbine output control unitcalculates in a process of determining the CSO. The load change ratecalculation unit 57 acquires a predetermined target rate of the outputchange with respect to the load change from the gas turbine outputcontrol unit. The coefficient calculation unit 58 acquires the weightingcoefficient from a correspondence table of the target rate and theweighting coefficient.

FIG. 9 is a diagram illustrating an example of a fuel distributioncontrol in the third embodiment according to the present invention.

The fuel distribution control of this embodiment will be described withreference to FIG. 9.

First, the load change rate calculation unit 57 calculates a load changerate (109). The load change rate calculation unit 57 outputs thecalculated load change rate to the coefficient calculation unit 58. Thecoefficient calculation unit 58 acquires a weighting coefficientaccording to the load change rate from a table or a function in whichthe load change rate and the weighting coefficient are associated witheach other on the basis of the acquired load change rate (110), andoutputs the weighting coefficient to the gas turbine output correctionamount calculation unit 56.

The gas turbine output correction amount calculation unit 56 calculatesa gas turbine output correction amount on the basis of a CSO, as in thesecond embodiment (106). The gas turbine output correction amountcalculation unit 56 multiplies the calculated gas turbine outputcorrection amount by the weighting coefficient according to the loadchange rate acquired from the coefficient calculation unit 58 tocalculate a gas turbine output correction amount according to the loadchange rate (111). The gas turbine output correction amount calculationunit 56 outputs the gas turbine output correction amount according tothe calculated load change rate to the gas turbine output predictionvalue calculation unit 51. The gas turbine output prediction valuecalculation unit 51 adds the gas turbine output value to the correctionamount acquired from the gas turbine output correction amountcalculation unit 56 to calculate a gas turbine output prediction value(108). Since subsequent processes are the same as those in the firstembodiment, description thereof will be omitted.

If a target rate is used in place of the load change rate, the loadchange rate calculation unit 57 acquires the target rate from the gasturbine output control unit (109), and outputs the target rate to thecoefficient calculation unit 58. The coefficient calculation unit 58calculates a weighting coefficient according to the target rate from atable or a function in which the target rate and the weightingcoefficient are associated with each other (110), and outputs theweighting coefficient to the gas turbine output correction amountcalculation unit 56. Subsequent processes are the same as those in acase in which the load change rate is used.

According to this embodiment, it is possible to obtain a gas turbineoutput correction amount according to a load change rate. Accordingly,it is possible to perform a distribution ratio control of the fuel onthe basis of a more accurate turbine inlet temperature estimation valueand further reduce a risk of occurrence of combustion vibration.

Fourth Embodiment

Hereinafter, a fuel control device according to a fourth embodiment ofthe present invention will be described with reference to FIGS. 10 to11.

FIG. 10 is a block diagram illustrating an example of the fuel controldevice of this embodiment.

As illustrated in FIG. 10, a fuel control device 50 in this embodimentincludes a load change rate determination unit 59 in place of thecoefficient calculation unit 58. Other configurations are the same asthat in the third embodiment.

The load change rate determination unit 59 acquires a load change ratecalculated by the load change rate calculation unit 57 and compares thevalue with a threshold value Q, which is set in advance and recorded inthe storage unit. If the load change rate is equal to or greater thanthe threshold value Q, the load change rate determination unit 59outputs a predetermined weighting coefficient P to the gas turbineoutput correction amount calculation unit 56. Further, if the loadchange rate is smaller than the threshold value Q, the load change ratedetermination unit 59 sets a value “0” as a weighting coefficient andoutputs the weighting coefficient to the gas turbine output correctionamount calculation unit 56. The threshold value Q is a value fordetermining whether a correction amount calculated by the gas turbineoutput correction amount calculation unit 56 is reflected in a gasturbine output value.

FIG. 11 is a diagram illustrating an example of a fuel distributioncontrol in the fourth embodiment according to the present invention.

A fuel distribution control of this embodiment will be described withreference to FIG. 11.

First, the load change rate calculation unit 57 calculates a load changerate (109). The load change rate calculation unit 57 outputs thecalculated load change rate to the load change rate determination unit59. The load change rate determination unit 59 determines whether theacquired load change rate is equal to or greater than the thresholdvalue Q. If the acquired load change rate is equal to or greater thanthe threshold value Q, the load change rate determination unit 59 readsthe weighting coefficient P from the storage unit and outputs theweighting coefficient P to the gas turbine output correction amountcalculation unit 56. Further, if the acquired load change rate issmaller than the threshold value Q, the load change rate determinationunit 59 outputs the value “0” to the gas turbine output correctionamount calculation unit 56 (112).

The gas turbine output correction amount calculation unit 56 calculatesa gas turbine correction amount on the basis of a CSO, similar to thesecond and third embodiments, and multiplies the gas turbine correctionamount by a weighting coefficient acquired from the load change ratedetermination unit 59 to calculate the gas turbine output correctionamount (111). The gas turbine output correction amount calculation unit56 outputs the calculated gas turbine output correction amount to thegas turbine output prediction value calculation unit 51. If the loadchange rate is smaller than the threshold value Q, the weightingcoefficient is “0”. Accordingly, the correction amount output by the gasturbine output correction amount calculation unit 56 is “0”. The gasturbine output prediction value calculation unit 51 adds the gas turbineoutput value to the correction amount acquired from the gas turbineoutput correction amount calculation unit 56 to calculate a gas turbineoutput prediction value (108). Since the correction amount is 0 if theload change rate is smaller than the threshold value Q, the gas turbineoutput prediction value calculation unit 51 outputs an actually measuredgas turbine output value to the turbine inlet temperature estimationunit 52. Since subsequent processes are the same as those in the firstembodiment, description thereof will be omitted.

According to this embodiment, it is possible to correct the gas turbineoutput value with the correction amount based on the CSO only in thecase of an intended load change on the basis of a magnitude of the loadchange rate. In actual operation, even when the output of the gasturbine is constant, a fuel calorie value change, a fuel supply pressurechange, or the like may occur, and the CSO may fluctuate with such achange. Then, in the case of the first to third embodiments, the turbineinlet temperature estimation value fluctuates under an influence of thefluctuating CSO. According to this embodiment, it is possible to reducethe risk of occurrence of combustion vibration caused by inappropriatelychanging the fuel distribution ratio with respect to such outercircumference conditions.

Fifth Embodiment

Hereinafter, a fuel control device according to a fifth embodiment ofthe present invention will be described with reference to FIGS. 12 to13.

FIG. 12 is a block diagram illustrating an example of a fuel controldevice of this embodiment.

As illustrated in FIG. 12, a fuel control device 50 in this embodimentincludes a load change rate calculation unit 57, a coefficientcalculation unit 58, and a load change rate determination unit 59. Otherconfigurations are the same as those in the second embodiment.

FIG. 13 is a diagram illustrating an example of a fuel distributioncontrol in the fifth embodiment according to the present invention.

The fuel distribution control of this embodiment will be described withreference to FIG. 13. This embodiment is a combination of the thirdembodiment and the fourth embodiment.

First, the load change rate calculation unit 57 calculates a load changerate (109). The load change rate calculation unit 57 outputs thecalculated load change rate to the coefficient calculation unit 58 andthe load change rate determination unit 59.

The coefficient calculation unit 58 determines a weighting coefficienton the basis of the load change rate, similar to the third embodiment(110). The coefficient calculation unit 58 outputs the weightingcoefficient to the load change rate determination unit 59.

The load change rate determination unit 59 determines whether the loadchange rate acquired from the load change rate calculation unit 57 isequal to or greater than the threshold value Q, and outputs theweighting coefficient according to the load change rate acquired fromthe coefficient calculation unit 58 to the gas turbine output correctionamount calculation unit 56 if the load change rate is equal to orgreater than the threshold value Q. Further, if the load change rate issmaller than the threshold value Q, the load change rate determinationunit 59 outputs the value “0” to the gas turbine output correctionamount calculation unit 56 (112).

The gas turbine output correction amount calculation unit 56 calculatesa gas turbine output correction value from a CSO, similar to the secondto fourth embodiments (106), and multiplies the gas turbine outputcorrection value by the weighting coefficient acquired from the loadchange rate determination unit 59 (111). The gas turbine outputprediction value calculation unit 51 acquires a value after themultiplication, and adds the value to an actually measured gas turbineoutput value to calculate a gas turbine output prediction value (108).

The turbine inlet temperature estimation unit 52 calculates a turbineinlet temperature on the basis of the gas turbine output predictionvalue calculated as above, an atmospheric temperature, an atmosphericpressure, and an IGV opening command value, and the fuel distributioncommand value calculation unit 53 determines a distribution ratio offuel that is supplied to each fuel system on the basis of the turbineinlet temperature.

According to this embodiment, it is possible to have all of the effectsof the second to fourth embodiments.

The turbine inlet temperature estimation unit 52 is an example of acombustion temperature estimation value calculation unit. Further, theatmospheric pressure or the atmospheric temperature is one example of anatmospheric condition. Further, the load change rate or the target rateis an example of a value indicating an output change of the gas turbineper unit time. Further, the IGV 14 is an example of a valve thatcontrols an amount of air that is mixed with the fuel and burned.

The fuel control device 50 described above includes a computer systemprovide therein. Each process in the fuel control device 50 describedabove is stored in a non-transitory computer-readable recording mediumin the form of a program, and the above processes are performed by acomputer reading and executing this program. Here, the computer-readablerecording medium refers to a magnetic disk, a magneto-optical disk, aCD-ROM, a DVD-ROM, a semiconductor memory, or the like. Further, thiscomputer program may be distributed to the computer via a communicationline, and the computer receiving this distribution may execute theprogram.

Further, the above program may be a program for realizing some of theabove-described functions. Further, the program may be a program capableof realizing the above-described functions in combination with a programpreviously stored in a computer system, that is, a differential file (adifferential program).

In addition, the components in the above-described embodiments can beappropriately replaced with well-known components without departing fromthe spirit and scope of the present invention. Further, the technicalscope of the present invention is not limited to the above embodiments,and various changes can be made without departing from the spirit andscope of the present invention.

INDUSTRIAL APPLICABILITY

According to the fuel control device, the combustor, the gas turbine,the control method, and the program described above, it is possible tosuppress a deviation between a target fuel system fuel ratio for aturbine inlet temperature and an actual fuel system fuel ratio even in atransient period of a load change.

REFERENCE SIGNS LIST

-   -   10 Gas turbine    -   11 Air compressor    -   12 Combustor    -   13 Turbine    -   14 IGV    -   15 Rotor    -   16 Power generator    -   17 Power meter    -   18 Pilot system fuel flow rate control valve    -   19 Main system fuel flow rate control valve    -   20 Top hat system fuel flow rate control valve    -   21 Fuel supply device    -   22 Pressure gauge    -   23 Thermometer    -   50 Fuel control device    -   51 Gas turbine output prediction value calculation unit    -   52 Turbine inlet temperature estimation unit    -   53 Fuel distribution command value calculation unit    -   54 Total fuel flow rate calculation unit    -   55 Valve opening degree calculation unit    -   56 Gas turbine output correction amount calculation unit    -   57 Load change rate calculation unit    -   58 Coefficient calculation unit    -   59 Load change rate determination unit

The invention claimed is:
 1. A fuel control device, comprising: acombustion temperature estimation value calculation unit thatproactively calculates a temperature estimation value according to aload change when a mixture of fuel and inflow air is burned using anatmospheric condition, an opening degree command value of a valve thatcontrols an amount of the inflow air that is mixed with the fuel andburned, and an output prediction value calculated on the basis of a fuelcontrol signal command value used for calculation of a total fuel flowrate flowing through a plurality of fuel supply systems; a fueldistribution command value calculation unit that calculates a fueldistribution command value indicating a distribution of fuel output fromthe plurality of fuel supply systems on the basis of the temperatureestimation value, and outputs the fuel distribution command value; and avalve opening degree calculation unit that calculates each valve openingdegree of a fuel flow rate control valve of the plurality of fuel supplysystems on the basis of the fuel distribution command value and thetotal fuel flow rate based on the fuel control signal command value,wherein a time delay of a turbine inlet temperature estimation value iscompensated by proactively calculating the temperature estimation value.2. The fuel control device according to claim 1, comprising: a gasturbine output prediction value calculation unit that calculates theoutput prediction value on a basis of a predetermined correspondencerelationship between the fuel control signal command value and a poweroutput value of a gas turbine.
 3. The fuel control device according toclaim 1, comprising: a gas turbine output correction amount calculationunit that calculates a gas turbine output correction amount forcorrecting the output prediction value on the basis of a predeterminedcorrespondence relationship between the fuel control signal commandvalue and a value for correcting an output of a gas turbine, and thefuel control signal command value; and a gas turbine output predictionvalue calculation unit that calculates the output prediction value usingan actually measured value of a power output value of the gas turbineand the gas turbine output correction amount.
 4. The fuel control deviceaccording to claim 3, comprising: a coefficient calculation unit thatcalculates a weighting coefficient for the gas turbine output correctionamount according to a value indicating an output change of the gasturbine per unit time.
 5. The fuel control device according to claim 3,comprising: a load change rate determination unit that detects an outputchange of the gas turbine per unit time and sets the gas turbine outputcorrection amount to 0 when the output change is smaller than apredetermined value.
 6. A combustor comprising the fuel control deviceaccording to claim
 1. 7. A gas turbine comprising the fuel controldevice according to claim
 1. 8. A control method for a fuel controldevice comprising: proactively calculating a temperature estimationvalue according to a load change when a mixture of fuel and inflow airis burned using an atmospheric condition, an opening degree commandvalue of a valve that controls an amount of the inflow air that is mixedwith the fuel and burned, and an output prediction value calculated onthe basis of a fuel control signal command value used for calculation ofa total fuel flow rate flowing through a plurality of fuel supplysystems; calculating a fuel distribution command value indicating adistribution of fuel output from the plurality of fuel supply systems onthe basis of the temperature estimation value, and outputs the fueldistribution command value; and calculating each valve opening degree ofa fuel flow rate control valve of the plurality of fuel supply systemson the basis of the fuel distribution command value and the total fuelflow rate based on the fuel control signal command value, wherein a timedelay of a turbine inlet temperature estimation value is compensated byproactively calculating the temperature estimation value.
 9. Anon-transitory computer-readable recording medium having a programstored therein, which when executed by a computer of a fuel controldevice causes the computer to perform steps comprising: proactivelycalculating a temperature estimation value according to a load changewhen a mixture of fuel and inflow air is burned using an atmosphericcondition, an opening degree command value of a valve that controls anamount of the inflow air that is mixed with the fuel and burned, and anoutput prediction value calculated on the basis of a fuel control signalcommand value used for calculation of a total fuel flow rate flowingthrough a plurality of fuel supply systems; calculating a fueldistribution command value indicating a distribution of fuel output fromthe plurality of fuel supply systems on the basis of the temperatureestimation value, and outputs the fuel distribution command value; andcalculating each valve opening degree of a fuel flow rate control valveof the plurality of fuel supply systems on the basis of the fueldistribution command value and the total fuel flow rate based on thefuel control signal command value, wherein a time delay of a turbineinlet temperature estimation value is compensated by proactivelycalculating the temperature estimation value.